1. Field of the Invention
This invention relates to a record memory medium having a recording layer comprising a photosensitive organic compound and recording/reading method comprising recording information by irradiating a photosensitive organic compound with light and reading out the information by light.
2. Description of the Prior Art
Heretofore, there have been known various record memory mediums for recording and reading out such as light disc, photomagnetic disc and the like. As the record receiving mediums, there are known rare earths-transition metal alloy thin films, reducing oxide thin films of chalcogen compounds utilizing phase transfer from amorphous state to crystalline state, heat mode recording mediums, thermoplastic recording mediums and the like. These mediums are formed on a substrate by coating, sputtering, vapor deposition or the like. It is required to make the film thickness of the recording layer as thin as possible so as to produce high density records. However, heretofore, the limit is about 300 .ANG. which is twice to twenty times as thick as the thickness of the film forming molecule. Heretofore, the distribution and orientation of molecules in the film are irregular so that the boundary between the light irradiated portion and the non-light irradiated portion is unclear upon writing-in with light. This causes a reduction in the S/N ratio due to blur of light slot when light is projected for reading out. Therefore, from the standpoint of sensitivity, it is desired that distribution and orientation of molecules in the film are uniform.